Process for preparing an alternate copolymer of butadiene and acrylonitrile

ABSTRACT

A new process for preparing an alternate copolymer of butadiene and acrylonitrile by contacting butadiene with acrylonitrile in liquid phase in the presence of the catalyst system comprising aluminum chloride, stannic chloride or zinc chloride as the first component, a vanadium compound or a chromium compound as the second component, and an organic peroxide as the third component.

United States Patent [19] Kawasaki et al.

[451 Aug. 28, 1973 PROCESS FOR PREPARING AN ALTERNATE COPOLYMER 0F BUTADIENE AND ACRYLONITRILE [75] Inventors: Akihiro Kawasaki; Masanobu Taniguchi; Tsuneto Nishiyama, all of Ichihara-shi; I-Iiroaki Ueda, Chiba-shi, all of Japan [73] Assignee: Maruzen Petrochemical Co., Tokyo,

Japan [22] Filed: Aug. 27, 1969 [21] App]. No.: 853,499

[30] Foreign Application Priority Data Sept. 5, 1968 Japan 43/63383 Sept. 5, 1968 Japan 43/63385 Dec. 10, 1968 Japan 43/89975 Dec. 26, 1968 Japan 43/94935 [52] US. Cl. 260/825, 260/823 [51] Int. Cl. C08d 1/4, C08d 3/02 [58] Field of Search 260/825 [56] References Cited OTHER PUBLICATIONS Symposium of Japanese Chemical Fibers Institute, 0c.- tober, 1968, No. 26, p. 83-96, Furakawa et al.

Primary Examiner-Joseph L. Schofer Assistant Examiner-William F. Hamrock Attorney-Flynn & Frishauf 5 7] ABSTRACT 10 Claims, No Drawings PROCESS FOR PREPARING AN ALTERNATE COPOLYMER OF BUTADIENE AND ACRYLONITRILE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a new process for copolymerizing butadiene and acrylonitrile and more particularly to a new process for preparing an alternate copolymer of butadiene and acrylonitrile which shows high elasticity. The alternate copolymer of this invention is useful in the fields of polymer, rubber and plastic industries, etc. The alternate copolymer of this invention is easily soluble in some kinds of organic solvents. It shows high rubber-like elasticity than the corresponding random copolymer of butadiene and acrylonitrile. Its glass transition temperature is lower than that of the conventional random copolymer.

2. Description of prior art As far as the inventors know, there is no prior art in connection with the process of preparing an alternate copolymer of butadiene and acrylonitrile.

DESCRIPTION OF THE INVENTION This invention is based on the discovery that by using a catalyst system comprising aluminum chloride as the first component, a vanadium compound or a chromium compound as the second component and an organic peroxide as the third component, acrylonitrile can be copolymerized with butadiene to produce a high molecular weight alternate copolymer. The detailed physical data are given in the copending application Ser. No. 836,736 filed June 26, 1969 now U. S. Pat. No. 3,658,775.

The composition of the copolymer according to elementary analysis substantially agrees with the calculated value for the 1:1 copolymer of butadiene and acrylonitrile. The copolymerization reaction gave 1:1 copolymer over a wide range of initial monomer compositions and also independently of polymerization time. The microstructure of butadiene unit in the copolymer was all trans-configuration. The NMR spectrum of the copolymer was shown to be very different from that of the conventional ultra high nitrile random copolymer of butadiene and acrylonitrile prepared by the prior art. Two strong peaks were observed at 7.71 'rand 7.89 in the NMR spectrum of the conventional ultra high nitrile random copolymer. On the other hand in the NMR spectrum of the 1:1 copolymer in this invention only one strong peak appears at 7.71 'rin this region. This means that block sequence of butadiene-butadiene is not substantially included in the copolymer of this invention. Consequently, each fact mentioned above supports the assumption that the present copolymer is an alternate copolymer of butadiene and acrylonitrile.

The alternate copolymer is easily soluble in chloroform, acetone and dimethylformamide at room temperature. This new alternate copolymer has many advantageous properties. For example, it shows higher rubbery elasticity than the conventional ultra high nitrile random copolymer and'its glass transition temperature is lower than that of the conventional random copolymer. The microstructure of butadiene unit in the conventional ultra high nitrile random copolymer is substantially transand 1.2-configurations. On the other hand, as described above, the microstructure of butadiene unit in this alternate copolymer is all transconfiguration. 1

Through the inventors study, the catalyst system formed from aluminum chloride and organic peroxide was also found to produce a 1:1 copolymer of butadiene and acrylonitrile. However,'most of the copolymer was only sparingly soluble in usual organic solvents. Therefore, the copolymer was very difficult to process. The IR spectrum of the chloroform soluble fraction of the copolymer was quite similar to that of the chloroform insoluble fraction and the microstructure of butadiene unit of the copolymer was all trans 1.4- configuration. The NMR spectrum of the chloroform soluble fraction showed no peak at 7.89p which would arise from the butadiene-butadiene sequence but showed astrong single peak at 7.71-r which would arise from the butadiene-acrylonitrile sequence. From the above results the copolymer was determined to be an alternate copolymer of butadiene and acrylonitrile. However, as described above, most of the copolymer is only sparingly soluble in the usual organic solvents.

On the other hand, the inventors also found that a two component catalyst system composed of stannic chloride and an organic peroxide or of zinc chloride and an organic peroxide was also found to produce copolymer of butadiene and acrylonitrile. However, the acrylonitrile/butadiene molar ratio of the copolymer was always lower than 1. Moreover most of the copolymer was only sparingly soluble in usual organic solvents. The chloroform soluble fraction of the copolymer contained a much higher content of the butadieneacrylonitrile repeating unit than did a random copolymer. The fraction showed a considerable amount of 7.891 peak in the NMR spectrum but still less than found in a random copolymer. While the copolymer contained butadiene unit prevalent in the trans 1.4-configuration, some butadiene units had the 1.2 configuration. As described above, most of the copolymer is only sparingly soluble in usual organic solvents and therefore the copolymer is not suitable for commercial use.

The detailed physical data are given in said copending application Ser. No. 836,736.

From the above results, it was found that by adding a vanadium or a chromium compound to the aluminum chloride-organic peroxide, stannic chloride-organic peroxide or zinc chloride-organic peroxide catalyst systems, an organic solvent soluble alternate copolymer of butadiene and acrylonitrile could be obtained, and, thus, this invention was completed.

The vanadium compound forming one component of the catalyst system of this invention is selected from any one having the formula OVCI; ,(OR), wherein n is a number from 0 to 3 and R is an alkyl, aryl or cycloalkyl group and a vanadium complex, for example, bis(cyclopentadienyl) vanadium, bis(cyclopentadienyl) vanadium chloride, bis(cyclopentadienyl)- vanadium dichloride, cyclopendadienylvanadium trichloride, cyclopentadienylvanadium dichloride oxide, tetracarbonyl cyclopentadienylvanadium, acetylacetonyl-vanadium dichloride oxide, triacetylacetonylvanadium oxide, diacetylacetonylvanadium chloride oxide, diacetylacetonylvanadium oxide, triacetylacetonylvanadium, etc. Chromium (VI) oxychloride is used as the chromium compound. Organic peroxides usable in this invention include alkyl peroxides, for example, tert-butyl peroxide, acyl peroxides, for example, benzoyl peroxide, and hydroperoxides, for example, cumene hydroperoxide.

Hydrocarbons, such as heptane, octane, isooctane, benzene, toluene, etc., chlorinated, hydrocarbons, such as methylene chloride, ethylene chloride, tetrachloroethane, tetrachloroethylene, ethylchloride, trichloroethylene, trichloroethane, etc., or a mixture of such solvents are used as diluent in preparing the catalyst.

and varying amounts of vanadium (V) oxychloride solution in methylene chloride (1 molar solution) were put successively in a 25 milliliter glass bottle at room temperature. Thereafter, the bottle was held in a low Preparation of the alternate copolymer of butadiene 5 temperature bath at -78 C and l millimole of alumiand acrylonitrile is carried out by contacting butadiene num chloride dissolved in 3.3 milliliters acrylonitrile with acrylonitrile in liquid phase in the presence of the and 4.0 milliliters liquid butadiene were put succesthree-component catalyst system described above. sively in the bottle also employing the usual dry air-free The copolymerization reaction is generally carried technique. Then the bottle was sealed and the monoout in the presence of a liquid organic diluent. Suitable l mers therein were allowed to polymerize at 25 C for diluents that can be used for the copolymerization are 16 hours. The amount of each individual catalyst comhydrocarbons, such as heptane, octane, isooctane, benponent is set forth in Table l.

i A TABLE 1 Reaction Monomers Catalysts" conditions C opolymer" AN in) onion AlCh vocn 132.0. Temp. Time Yield (1211.) (mL) (1111.) (mmol) (mmol) (mmol) C.) (hr.) 0;.) (dl."g.)

3.3 4. 0 a l 0. 0a 0. 25 16 0. 52 3.3 4.0 3 1 0.20 0.5 25 1e 0. 32 0.0 3.3 4.0 a 1 0 05 25 2a 0.26

AN: acrylonitrilc: BD: liquid butndiene.

" B.P.O.: benzoyl peroxide.

zene, toluene, etc; chlorinated hydrocarbons, such as methylene chloride, ethylene chloride 'tetrachloroethane, tetrachloroethylene, ethylchloride, trichloroethylene, trichloroethane, etc; or a mixture of such dilucuts.

The temperature of the copolymerization process can be varried over a wide range, generally from -l 00 C to +60 C and preferably from 70 C to +40 C. Sufficient pressure is employed to keep the monomers in liquid condition regardless whether a diluent is present in the reaction mixture or not.

In general, the molar ratio of butadiene to acrylonitrile in the initial monomer composition will be from :80 to 80:20 the preferred ratio being 50:50.

After the polymerization is complete, the reaction product is separated from the reaction tube and treated to separate the diluent and unreacted monomers. The alternate copolymer is then treated to remove the catalyst residue, which treatment may comprise mixing the chloroform solution of the copolymer with an acidified methanol. The acid which is used to acidify methanol is a mineral acid such as hydrochloric acid. Thereafter, the deposited solid copolymer may be washed with methanol several times and may be dried under vacuum. A small amount of butadiene homopolymer may be involved in the reaction product; this is easily removed by washing the reaction product with diethyl ether.

The following examples illustrate the preparation of the alternate copolymer of butadiene and acrylonitrile in accordance with this invention.

EXAMPLE 1 Employing the usual dry air-free technique, 0.5 millimole benzoyl peroxide, 3 milliliters methylene chloride Reference 1 shows the result obtained by the catalyst system formed by leaving out VOC]; from the AlCl -B.P.O.-VOCl catalyst system.

All copolymers in Table l were determined to be 1:1 copolymers of butadiene and acrylonitrile from their elementary analysis and the microstructures of butadiene unit in these copolymers were found to be all trans 1.4-structure from their IR data. They were also confirmed to be alternate copolymers of butadiene and acrylonitrile from their NMR data showing no 7.91- peak arising from the methylene groups of butadienebutadiene sequence. However, the copolymers in Exp. No. l and 2 were all easily soluble in chloroform and acetone at room temperature. On the other hand, most of the copolymer in Reference 1 was only sparingly soluble in the usual organic solvents. Therefore, the copolymer of reference 1 is very difficult to process. Moreover, it is observed in Table 1 that by adding VOCl to the AlCl -B P.O. catalyst system, yield of the alternate copolymer increases.

EXAMPLE 2 Employing the usual dry air-free technique, 0.5 millimole benzoyl peroxide, 3 milliliters toluene and varying amounts of vanadium (V) oxychloride solution in toluene (l molar solution) were put successively in a 25 milliliter glass bottle at room temperature. Thereafter, the bottle was held in a low temperature bath at 78 C and l millimole of aluminum chloride dissolved in 3.3 milliliters acrylonitrile and 4.0 milliliters liquid butadiene were put successively in the bottle also employing the usual dry air-free technique. Then, the bottle was sealed and the contents allowed to polymerize at 25 C for 16 hours. The amount of each individual catalyst component is set forth in Table 2.

AN: acrylonitrile: BD: liquid butadienc.

" B.P.O.: benzoyl peroxide.

[n]: intrinsic viscosity in chloroform at 30 C.

Reference 1 shows the result obtained by the catalyst system formed by leaving VOCl out of the AlCl -B.P.O.-VOCl catalyst system.

All copolymers in Table 2 were determined to be 1:1 copolymers of butadiene and acrylonitrile from their elementary analysis and the microstructures of butadiene unit in these copolymers were found to be all trans 1.4-structure from their IR data. They were also confirmed to be an alternate copolymers of butadiene and acrylonitrile from their NMR data showing no 7.91 peak arising from methylene groups of butadienebutadiene sequence. However, most of the copolymers in Exp. No. 1 and 2 were all easily soluble in chloroform and acetone at room temperature. On the other hand the copolymer in Reference 1 was only sparingly soluble in the usual organic solvents. Therefore, the latter copolymer is very difficult to process. Moreover, it is observed in Table 2 that by adding VOCl to the AlCl -B.P.O. catalyst system, yield of the alternate copolymer increases.

EXAMPLE 3 Employing the usual dry air-free technique, 0.5 millimole benzoyl peroxide, varying amounts of methylene chloride and varying amounts of vanadium (V) oxychloride solution in methylene chloride (1 molar solu- 25 ity of the copolymer was sparingly soluble in usual organic solvents. However, the chloroform soluble fraction of the copolymer contained a much higher content of the butadiene-acrylonitrile repeating unit than did a random copolymer. This fraction showed a considerable amount of the 7.97 peak in the NMR spectrum but still less than found in a random copolymer. A sharp peak at 8.21, which is characteristic of the alternating unit, was also present. While the copolymer contained butadiene unit prevalently in the trans 1.4-structure, some butadiene units had the 1.2-structure.

From above results it is found that by adding VOCl to the SnCl -B.P.O. catalyst system, solubility and degree of alternation of the copolymer obtained are both increased.

EXAMPLE 4 Employing the usual dry air-free technique, 2 milliliters methylene chloride, 12.5 millimoles zinc chloride and 1.7 milliliters acrylonitrile were put successively in a milliliter glass bottle at room temperature. Thereafter, the bottle was held in a low temperature bath at 78 C and 0.5- millimole benzoyl peroxide, 1 milliliter vanadium (V) oxychloride solution in methylene chloride (1 molar solution) and 2.0 milliliters liquid butadiene were put successively in the bottle also employing the usual dry air-free technique. Then, the bottle was sealed and the contents allowed to polymerize at 25 C for 17 hours. 0.40g acetone and chloroform soluble alternate copolymer of butadiene and acrylonitrile was obtained. lts intrinsic viscosity was 0.4 (dl/g) in chloroform at C.

EXAMPLE 5 Employing the usual dry air-free technique, 0.5 millimole benzoyl peroxide, 3 milliliters methylene chloride TABLE 3 Reaction Monomers Catalysts conditions Copol vmer" Dlluent AN BD CHgClg SnCh VOCl; B.P.O. Temp. Time Yield [1 (1111 l (1111.) (1111.) (11111101) (11111101) (11111101) C.) (l1r.) (g (dL/g.)

4. 0 3 1 0. 05 0. 1 25 10 0. 20 0. 3 4. 0 3 1 0. 2O 0. 5 25 16 0. 20 0. 3 4. 0 .Z l 1. 0O 0. 5 23 113 0. 54 0. b 4. 0 1 l 2. 00 0. 5 23 10 0. 41 4. 0 3 1 0 0. a 16 0. l5

AN: acrylonitrile; 13D: liquid butadiene.

" ll.l.0.: benzoyl peroxide.

"' intrinsic viscosity in chloroform at 30 C.

Reference 1 showsthe result obtained by the catalyst system formed by leaving out VOCl from the SnCl -B.P.O.-VOCl catalyst system.

The copolymersin Exp. No. 1 4 were alldetermined to be alternate copolymers of butadiene and acrylonitrile from their NMR data and the microstructures of butadiene unit in these copolymers were found to be all trans 1.4-structure from their LR. spectra. These alternate copolymers were easily soluble in chloroform and acetone at room temperature.

On the other hand, the copolymer in Reference 1 contained mole percent acrylonitrile and the majorand varying amounts of chromium (V1) oxychloride solution in methylene chloride (1 molar solution) were put successively in a 25 milliliter glass bottle at room temperature. Thereafter, the bottle was held in a low temperature bath at 78 C and l millimole of aluminum chloride dissolved in 3.3 milliliters acrylonitrile and 4.0 milliliters liquid butadiene were put successively in the bottle also employing the usual dry air-free technique. Then, the bottle was sealed and the contents allowed to polymerize at 35 C for 16 hours. The amount of each individual catalyst component is set forth in Table 4.

TABLE 4 I Reaction Monomers v Catalysts conditions copolymer AN BD CIIQC]? AlCl; ClOgC-l: B.P.0. Temp. Time Yield [1 (ml.) (ml.) (ml.) (mmol) (mmol) (mmol) C.) (hr.) (g) tdlJg.)

Exp. Z\0

1 3. 3 4. 0 3 1 0. 05 0. 05 35 16 0. T8 2 3. 3 4. 0 3 1 0. 50 0. 05 35 16 0. 87 Reference 1. 3. 3 4. 0 3 1 0 0. 05 35 16 0. 39

' AN: acrylonitrile; 13D: liquid butadiene.

" B.P.O.: benzoyl peroxide.

Reference 1 shows the result obtained by the catalyst temperature- Thereafter, the bottle was held in a W system f d b l i out c o cl f the temperature bath at 78 C and l millimole of stannic Alm -BR() -(j (j] catalyst system chloride dissolved in 3.3 milliliters acrylonitrile and 4.0

All copolymers in Table 4 were determined to b 1- milliliters liquid butadiene were put successively in the temate copolymers of butadi n d l i il 5 bottle also employing the usualdry air-free technique. spectively. However, the copolymers in Exp. No. 1 and Then, the bottle was Sealed d t COfltentS allD ed t0 2 were all easily soluble in chloroform and acetone at polymerize at 35 C for 16 hours. The amount of each room temperature. On the other hand, most of the coindividual catalyst component set forth in Table 6.

' TABLE 6 Reaction Monomers" Catalysts conditions Copol \'1ner' AN BD CHQClZ SnClq CIOQCI: B.P.O. Temp. Time (1111.) (1111.) (1111.) (mmol) (mlnol) (nnnol) r. C.) (hr.)

Exp. No

1 3 .3 4.0 s 1 0.05 0.5 as 16 2 3 .3 4.0 3 1 0. 50 0.5 35 16 Reference 1. 3. 3 4. 0 3 l 0 0. 5 35 16 AN: acrylonitrile; BD liquid butadienc. "B.P.O.: benzoyl peroxide. "[v;]: intrinsic viscosity in chloroform at 30 C.

polymer in Reference 1 was only sparingly soluble in 20 Reference 1 shows the result obtained by the catalyst the usual organic solvents. Moreover, it is observed in system formed by leaving out CrO Cl from the Table 4 that by adding CrO,Cl, to the AlCl -B.P.O. cat- SnCl,-B.P.O.-CrO Cl catalyst system. The copolymer alyst system, yield of the alternate copolymer increases. in Reference 1 contained 45 mole percent acrylonitrile and most of the copolymer was only sparingly soluble m 6 I in the usual organic solvents. However, the chloroform p y the usual dry l fi techmquevo-s soluble fraction of the copolymer contained a much mQle benzoyl Peroxide 3 heptane and vary higher content of the butadiene-acrylonitrile repeating ing amounts of chromium (Vi) oxychloride solution in i than i a random copolynmL The f ti heptanc molar Solution) were p successively in a showed a considerable amount of the 7.91 peak in the 25 glass bottle at room temperature. Thereaf- 3O spectrum but still less than found in a random coter, the bottle was held in a low temperature bath at l A sharp k at 3,2 hi h i haracteristic 78 C and l millimole of aluminum chloride dissolved f h alternating unit, was also present. in 3.3 milliliters acrylonitrile and 4.0 milliliters liquid The copolymers in Exp, N0, 1 and 2 were all deterbutadiene were put successively in the bottle also emmined to be alternate copolymers of butadiene and acploying the usual dry air-free technique. Then, the botrylonitrile from their NMR data and the microstructle was sealed and the contents allowed to polymerize tures of butadiene unit in these copolymers were found at 35 C for 16 hours. The amount of each individual to be all trans 1.4-structure from their lR data. These catalyst component is set forth in Table 5. alternate copolymers were easily soluble in chloroform TABLE 5 V Reaction Monomers Catalysts conditions copolymer AN D Heptane AlCl CrOzClg B.P. Temp. Time Yield [11} (1111.) (rnl.) (mL) (mmol) (mmol) (mmol) C.) (hr.) (g.) (dL/g.)

Exp. No

1. 3.3 4.0 3 1 0. 0.5 35 16 3.3 4.0 3 1 1.00 0.5 35 16 Reference 1... 3.3 4.0 1 0 0.5 35 16 AN: acrylonitrile; BD: liquid butadiene. B.P.O.; benzoyl peroxide. [r1]! intrinsic viscosity in chloroform at 30 C.

Reference 1 shows the result obtained by the catalyst and acetone at room temperature.

system formed by leaving out CrO Ch from the From the above results it is found that by adding AlCl -B.P.O.-CrO Cl catalyst system. CrO Cl, to the SnCl -B.P.O. catalyst system, solubility All copolymers in Table 5 were determined to be aland degree of ternation of the copolymer obtained temate copolymers of butadiene and acrylonitrile reare both C easedspectively. However, the copolymers in Exp. No. l and 2 were all easily soluble in chloroform and acetone at EXAMPLE 8 room temperature. On the other hand, most of the co- Employing the usual y air-free technique, millipolymer in Reference 1 was only sparingly soluble in {Hole benzoyl p 3 milliliters heptane and y the usual organic solvents. Moreover, it is observed in 8 amounts of oxychlofide Solution in Table 5 that by adding Cr0 Cl to the AlCl -H.P.O. cathcpmc molar Solution) were 1 succcssivcly in a alyst System, yield of the ahemate copolymer increases 25 milliliter glass bottle at room temperature. Thereafter, the bottle was held in a low temperature bath at EXAMPLE 7 78 C and l millimole of stannic chloride dissolved in 3.3 milliliters acrylonitrile and 4.0 milliliters liquid bu- Employing the usual y air-free technique, millitadiene were put successively in the bottle also employmole benzoyl peroxide, 3 milliliters methylene chloride ing the usual dry air-free technique. Then, the bottle and varying amounts of chromium (VI) oxychloride sowas sealed and the contents allowed to polymerize at lution in methylene chloride (1 molar solution) were 35 C for 16 hours. The amount of each individual cataput successively in a 25 milliliter glass bottle at room lyst component is set forth in Table 7 TABLE 7 Reaction Monomers Catalysts conditions Copolymcr AN BD Heptane SnCh CIOgCl: B.P.O. Temp. Time Yield [1,] (1111.) (n1l.) (n11.) (m111o1) (11111101) (11111101) C.) (In) (g.) (dL/g.)

Exp. X

1 3.3 4.0 3 1 0. 50 0.5 35 16 1. 29 2 3. 3 4. 0 3 l 1. 00 0. 35 16 1. 80 Reference 1... 3. 3 4. 0 3 1 0 0. 5 35 16 0.20

AN: acrylonitrile; BD: liquid butadiene.

"B.P.0.: benzoyl peroxide.

"11 1: intrinsic viscosity in chloroform at 30 C.

Reference 1 shows the result obtained by the catalyst system formed by leaving out 010,01, from the SnCl,-B.P.O.-CrO,Cl, catalyst system. The copolymer in Reference 1 contained 45 mole percent acrylonitrile and most of the copolymer was only sparingly soluble in the usual organic solvents. However, the chloroform soluble fraction of the copolymer contained a much higher content of the butadiene-acrylonitrile repeating unit than did a random copolymer. The fraction showed a considerable amount of the 7.91- peak in the NMR spectrum but still less than found in a random copolymer. A sharp peak at 8.21, which is characteristic of the alternating unit, was also present.

The copolymers in Exp. No. l and 2 were all determined to be alternate copolymers of butadiene and acrylonitrile from their NMR data and the microstructures of butadiene unit in these copolymers were found to be all trans 1.4-structure from their IR data. These alternate copolymers were easily soluble chloroform and acetone at room temperature.

F mm above results it is found that by adding CrO,Cl to the SnCl -B.P.O. catalyst system, solubility and degree of alternation of the copolymer obtained are both increased.

EXAMPLE 9 Employing the usual dry air-free technique, 2 milliliters methylene chloride, 1.7 milliliters acrylonitrile, l millimole aluminum chloride, 0.5 millimole benzoyl peroxide, varying amounts of triethoxy vanadium oxide (OV(OC H solution in toluene (1 molar solution) and 2.0 milliliters liquid butadiene were put successively in a 25 milliliter glass bottle at 78 C. Then, the bottle was sealed and the contents allowed to polymerize at C for 16 hours. The amount of each individual catalyst component is set forth in Table 8.

peroxide and 2.0 milliliters liquid butadiene were put successively in the bottle also employing the usual dry air-free technique. Then, the bottle was sealed and allowed to polymerize at 35 C for 16 hours. 0.64g acetone and chloroform soluble alternate copolymer of butadiene and acrylonitrile was obtained. Its intrinsic viscosity was found to be 0.62 (dl/g) in chloroform at 30 C.

EXAMPLE 1 l Employing the usual dry air-free technique, 0.5 millimole triacetylacetonylvanadium ((C H O V) and 2 milliliters methylene chloride were put successively in a 25 milliliter glass bottle at room temperature. Thereafter, the bottle was held in a low temperature bath at 78 C and l milliliter stannic chloride solution in methylene chloride (1 molar solution), 1.7 milliliters acrylonitrile, 0.5 millimole benzoyl peroxide and 2.0 milliliters liquid butadiene were put successively in the bottle also employing the usual dry air-free technique. Then the bottle was sealed and allowed to polymerize at 35 C for 16 hours. 0.27g acetone and chloroform soluble alternate copolymer of butadiene and acrylonitrile was obtained. Its intrinsic viscosity was found to be 0.22 (dl/g) in chloroform at 30 C.

EXAMPLE l2 Employing the usual dry air-free technique, 2.0 millimoles triacetylacetonylvanadium ((C H O V) and 2 milliliters methylene chloride were put successively in a 25 milliliter glass bottle at room temperature. There after, the bottle was held in a low temperature bath at 78 C and 12.5 millimoles zinc chloride, 1.7 milliliters acrylonitrile, 0.5 millimole benzoyl peroxide and 2.0 milliliters liquid butadiene were put successively in the bottle also employing the usual dry air-free technique.

TABLE 8 Monomers Catalysts Reaction Copolymer conditions AN 13D CHgClz AlCl; OV(OC II B.P.O. Temp. Tlmc Yield 11;] (1111.) (1111.) (n1l.) (11111101) (11111101) (11111101) C.) (11r.) (g.) (d1./g.)

Exp. \0

1 l. 7 2. 0 .2 1 0. 01 O. 5 10 16 O. 21 1.19

' ANzacrylouitrilc; BDzbutadlenc. 11.P.O.: benzoyl peroxide. [1 intrinsic viscosity in chloroform at 30 C.

The copolymers in Exp. No. l-3 were all found to be a chloroform soluble alternate copolymer of butadiene and acrylonitrile respectively.

EXAMPLE l0 Employing the usual dry air-free technique, 0.02 millimole triacetylacetonylvanadium ((C H O,) V) and 2 milliliters methylene chloride were put successively in a 25 milliliter glass bottle at room temperature. Thereafter, the bottle was held in a low temperature bath at 78 C and l millimole of aluminum chloride dissolved in 1.7 milliliters acrylonitrile, 0.5 millimole benzoyl oxide (OV(C H and 2 milliliters methylene chloride were put successively in 25 milliliters glass bottle at room temperature. Thereafter the bottle was held in a low temperature bath at 78 C and l milliliter stannic chloride solution in methylene chloride (1 molar solution), 1.7 milliliters acrylonitrile, 0.5 millimole benzoyl peroxide and 2.0 milliliters liquid butadiene were put successively in the bottle also employing the usual dry air-free technique. Then the bottle was sealed and the monomers therein were allowed to polymerize at 25 C for 7 hours. 0.13g acetone and chloroform soluble alternate copolymer of butadiene and acrylonitrile was obtained. Its intrinsic viscosity was found to be 0.32 (dl/g) in chloroform at 30 C.

What is claimed is:

l. A process for preparing an alternate copolymer of butadiene and acrylonitrile by contacting acrylonitrile and butadiene successively in a non-aqueous liquid phase in the presence of the catalyst system comprising a metal chloride selected from the group consisting of aluminum chloride, stannic chloride and zinc chloride as a first component, a compound selected from the group consisting of a vanadium compound having the general formula OVCI (OR),, wherein n is a number from to 3 and R is selected from the group consisting of alkyl, aryl and cycloalkyl groups, a vanadium complex selected from the group consisting of bis(cyclopentadienyl) vanadium, bis(cyclopentadienyl) vanadium chloride, bis(cyclopentadienyl) vanadium dichloride, cyclopentadienyl vanadium trichloride, cyclopentadieny] vanadium dichloride oxide, tetracarbonyl cyclopentadienyl vanadium, acetylacetonyl vanadium dichloride oxide, triacetylacetonyl vanadium oxide, diacetylacetonyl vanadium chloride oxide, diacetylacetonyl vanadium oxide, triacetylacetonyl vanadium and chromium (VI) oxychloride as a second component, and an organic peroxide selected from the group consisting of an alkyl peroxide, an acyl peroxide and a hydroperoxide as a third component.

2. A process of claim I, wherein the vanadium compound is VOCI 3. A process of claim 1 wherein the vanadium compound-is selected from the group consisting of acetyl acetonyl vanadium dichloride oxide, diacetyl acetonyl vanadium oxide, diacetyl acetonyl vanadium chloride oxide, diacetyl acetonyl vanadium oxide and triacetyl acetonyl vanadium.

4. A process of claim 1, wherein the chromium compound is CrO Cl 5. A process of claim 1, wherein the copolymerization reaction is carried out in the presence of a diluent selected from the group consisting of hydrocarbons, chlorinated hydrocarbons and a mixture thereof.

6. A process of claim 1, wherein the molar ratio of butadiene to acrylonitrile in the initial monomer composition is within the range from 20 :80 to 80 20.

7. A process of claim 1, wherein the polymerization temperature is within the range of from about C. to about +60 C.

8. A process of claim 3, wherein the copolymerization temperature is from about 70 C. to +40 C.

9. A process of claim 8, wherein the molar ratio of butadiene to acrylonitrile in the initial monomer composition is about 50:50.

10. A process for preparing an alternate copolymer of butadiene and acrylonitrile by contacting first acrylonitrile and then butadiene in a non-aqueous liquid medium in the presence of a catalyst comprising a metal chloride selected from the group consisting of aluminum chloride and zinc chloride as one component,

and an organic peroxide selected from the OVCI ,,(OR),, wherein n is a number 0 to 3 and R is selected from the group consisting of alkyl, aryl and cycloalkyl groups as a second component, and an organic peroxide selected from the group consisting of an alkyl peroxide, an acyl peroxide and a hydroperoxide as a third component. 

2. A process of claim 1, wherein the vanadium compound is VOCl3.
 3. A process of claim 1 wherein the vanadium compound is selected from the group consisting of acetyl acetonyl vanadium dichloride oxide, diacetyl acetonyl vanadium oxide, diacetyl acetonyl vanadium chloride oxide, diacetyl acetonyl vanadium oxide and triacetyl acetonyl vanadium.
 4. A process of claim 1, wherein the chromium compound is CrO2Cl2.
 5. A process of claim 1, wherein the copolymerization reaction is carried out in the presence of a diluent selected from the group consisting of hydrocarbons, chlorinated hydrocarbons and a mixture thereof.
 6. A process of claim 1, wherein the molar ratio of butadiene to acrylonitrile in the initial monomer composition is within the range from 20 :80 to 80 :
 20. 7. A process of claim 1, wherein the polymerization temperature is within the range of from about -70* C. to about +60* C.
 8. A process of claim 3, wherein the copolymerization temperature is from about -70* C. to +40* C.
 9. A process of claim 8, wherein thE molar ratio of butadiene to acrylonitrile in the initial monomer composition is about 50:50.
 10. A process for preparing an alternate copolymer of butadiene and acrylonitrile by contacting first acrylonitrile and then butadiene in a non-aqueous liquid medium in the presence of a catalyst comprising a metal chloride selected from the group consisting of aluminum chloride and zinc chloride as one component, and an organic peroxide selected from the OVCl3-n(OR)n wherein n is a number 0 to 3 and R is selected from the group consisting of alkyl, aryl and cycloalkyl groups as a second component, and an organic peroxide selected from the group consisting of an alkyl peroxide, an acyl peroxide and a hydroperoxide as a third component. 